<html>
<head>
   <title>单元格</title>
<head>
<body>
  <center>
     <table border="1">
        <tr>
          <td>A1</td> <td colspan="2">A2A3</td><td>A4</td>
         </tr>
        <tr>
          <td>c1</td><td>c2</td><td>c3</td><td>c4</td>
         </tr>
        </table>
    </center>
</body>
</html>
